TITLES AND ABSTBACTS OF PAPERS 135 



The final matter of business was the consideration of the invitation of 

 the Pacific Coast Section to hold either a regular or extra meeting of the 

 Society in the vicinity of San Francisco during the summer of 1915. The 

 Council suggested that the Pacific Coast Section be empowered to call an 

 extra meeting for this time, which suggestion was formally adopted by 

 the members. 



There being no further matters of business, the members then pro- 

 ceeded to the reading of papers in two sections : first, Vertebrate Paleon- 

 tology and, second, Invertebrate, Paleobotanic, and General Paleontology. 

 The minutes of the vertebrate section are given on pages 139 to 145. 



SECTION OF INVEETEBEATE^ PALEOBOTANIC^ AND GENERAL PALEONTOLOGY 



The first paper of this section was presented by the author and illus- 

 trated with lantern slides; 25 minutes. Discussed by A. W. Crabau, 

 A. F. Foerste, E. T. Jackson, with reply by Miss Wood. 



USE OF CRINOID ARMS IN STUDIES OF PHYLOGENY 

 BY ELVIEA WOOD 



{Abstract) 



It has been found, in studying the phylogeny of Paleozoic crinoids, that the 

 few young individuals preser^^ed are usually too far advanced in development 

 to show stages in ontogeny which can be used for working out the phylogeny 

 of the group to which they belong. The student is thus restricted to Infor- 

 mation to be obtained from adults. The number and arrangement of calyx 

 plates in the species of closely related genera show so little variation that they 

 do not give definite stages in ontogeny. A study of the arms of crinoids has 

 shown that in some species the arm, from the proximal to the distal portion, 

 passes through a series of stages which, taken in connection with other char- 

 acters, may be used to determine the phylogeny of the group to which the 

 species belongs. The genus Cactocrinus has furnished an illustration of these 

 facts, and the phylogeny of the genus and its relation to Teleiocrinus has been 

 indicated as far as the material available for study will permit. 



The next paper was presented by the senior author without, manuscript 

 and illustrated by charts, maps, and specimens; 15 minutes. Discussed 

 by Charles Schuchert and John M. Clarke. 



WESTERN EXTENSION OF SOME PALEOZOIC FAUNAS IN SOUTHEASTERN 



MISSOURI 



BY STUART WELLER AND M. G. MEHL 



(Abstract) 



The Mississippian sediments in southern Missouri in most localities lie un- 

 conformable on formations of Ordovician age, but in Ste. Genevieve County, 



